21220343412 has 24 divisors (see below), whose sum is σ = 49563825696. Its totient is φ = 7066349088.

The previous prime is 21220343377. The next prime is 21220343429. The reversal of 21220343412 is 21434302212.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 874878 + ... + 898805.

It is an arithmetic number, because the mean of its divisors is an integer number (2065159404).

Almost surely, 2^21220343412 is an apocalyptic number.

It is an amenable number.

21220343412 is an abundant number, since it is smaller than the sum of its proper divisors (28343482284).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21220343412 is a wasteful number, since it uses less digits than its factorization.

21220343412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1774687 (or 1774685 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 24.

Adding to 21220343412 its reverse (21434302212), we get a palindrome (42654645624).

The spelling of 21220343412 in words is "twenty-one billion, two hundred twenty million, three hundred forty-three thousand, four hundred twelve".